understanding the behavior of anomalies is inseparable from progress in understanding the processes maintaining the mean transports of heat, fresh water, and chemical constituents.

  • What are the dec-cen fluctuations of circulation structure and intensity and water mass pathways? How are they affected by surface forcing? What are the mechanisms of the fluctuations? What are the relative roles, including the interaction of wind, thermal, and haline forcing? What are the surface expressions of these fluctuations? A number of processes are thought to modulate the intensity of meridional heat transport, as effected by gyre circulations and western boundary currents. These processes include eddy-driven (subbasin- and basin-scale) recirculations and the remote influence of wind stress and buoyancy anomalies via Rossby and coastal waves. What are the relative roles of these processes in dec-cen variability of heat transport and SST? What is the role of salinity advection feedback to surface freshwater anomalies when heat transport and SST anomalies exist?

  • What feedback and coupling mechanisms maintain SST, heat, fresh water, sea ice, and chemical anomalies on dec-cen timescales? How do anomalies survive the seasonal cycle to reappear in subsequent winters, in particular, providing the observed long-lived recurrent winter SST anomalies? How do the histories of water masses evolve at higher latitudes, where sequestering is only seasonal, so that in winter there are recurrent advected heat content anomalies manifested as SST anomalies propagating downstream through the warm-to-cold water transformation pathways? What mechanisms control the strength, heave, and wobble of gyres on dec-cen timescales?

  • What are the mechanisms of region-to-region and basin-to-basin interaction on dec-cen timescales? What mechanisms control the magnitude and other characteristics of waters exchanged among the oceanic circulation gyres and thus the amplitude and property fluxes of the full ocean overturning circulation? Can the variability of this overturning circulation be measured? Decadal change evidence focuses mainly on isolated gyre or paired gyre-gyre phenomena—do more global patterns and interactions occur on interdecadal to century timescales? Are there unique patterns for Southern Ocean participation in dec-cen climate variability, reflecting the circumpolar flow and linkages provided by the Antarctic Circumpolar Current, including the effects on adjacent basins' subtropical gyres? What are the processes connecting tropical SST and the extratropical Pacific? What oceanic processes modify ENSO events on deccen timescales?

  • How is carbon partitioned in the ocean and what are the roles of physical processes in the carbon flux? What are the major processes controlling the partitioning of carbon among ocean reservoirs and between the ocean

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